The instant invention relates to horse back riding, and in particular relates to a stirrup suspension including a first suspension spring designed to absorb the downward forces attendant to normal riding conditions, and a second more rigid suspension spring designed to absorb the additional downward forces developed during jumping.
Typical equestrian riding gear includes a saddle, and stirrups attached to the saddle for receiving the feet of a rider. The weight of an individual seated upon the saddled horse is distributed through the saddle and the stirrups. In forward motion of the horse, the rider""s feet in the stirrups act as a natural suspension system through flexion of the ankle joints. The rider places the ball of his foot on the base of the stirrup and by the controlled flexion of the ankle joint, the rider can create a natural suspension system. This type of riding is most prevalent in English riding, and especially in jumping. Sufficient suspension of the rider is necessary to maintain proper balance for performance purposes as well as safety. In addition, proper suspension avoid unnecessary adverse contact of the rider on the horse""s back thereby avoiding injury to the horse. In jumping, the problem is compounded by increased vertical forces generated by vertical movement of the rider""s weight, and a concentration of those forces directly through the stirrups. The amount of downward pressure on the stirrups is dependent upon the rider""s weight, forward momentum, position, the amount of contact in the seat of the saddle and the height of the jump. The amount of downward forces increases dramatically upon take-off and landing. Accordingly, an individual needs to physically create sufficient natural suspension in two stages: 1) when approaching a jump or shortly after landing; and 2) at take-off and landing of the jump. In stage 1, for example, a 160 lb. rider might create between 25 and 125 lbs./sq.in. of downward force in each stirrup depending on body contact in the saddle. However, when jumping, the rider disperses the weight primarily through the stirrups and generates a significantly higher downward force, which depending on the height of the jump and weight of the rider, can reach up to 300 lbs./sq.in.
The forces generated during riding and jumping should be absorbed through the ankle""s natural suspension. However, the drawback to the ankle""s natural suspension is that is relies on the physical limitations of the rider. Effectiveness in executing this riding style depends highly on physical flexibility, range of motion, strength, posture, and experience of the rider. Insufficient flexibility and range of motion will clearly result in inferior riding, loss of balance, and potential injury to the horse and/or rider. This is especially apparent in show jumping. In competitive show jumping, a rider navigates around a course containing several jumps, usually more than a dozen, which are set at prescribed heights depending upon the qualifications of the rider. Therefore, in this environment a rider would encounter both normal riding conditions and jumping conditions rapidly interchanging and would experiences frequent and substantial variations in downward force. Rider""s with poor ankle control and flexion are often referred to as having xe2x80x9cstiff ankles.xe2x80x9d The most frequent recommendation to improve strength and flexibility is physical therapy, that is exercises to both strengthen the ankle and calf muscles and to stretch the Achilles tendon to expand range of motion.
The prior art has also attempted to provide a variety of energy absorbing devices to remedy the xe2x80x9cstiff anklexe2x80x9d problem. These devices have included stirrup suspensions with springs and shock absorbers. While these solutions are effective in some specialized circumstances, they have not yet been widely adopted in the art, and there is thus believed to be a need in the industry, and especially for competitive show jumping, for an improved multi-stage stirrup suspension that can accommodate the different downward forces generated during normal riding as well as jumping.
In this regard, the instant invention provides an improved stirrup suspension that utilizes a multi-stage spring suspension to accommodate the different downward forces generated during normal riding as well as jumping. The stirrup suspension includes a housing, a slide member slidably received within the housing, a stirrup connector mounted to the lower end of the slide member, a first spring element received around the slide member, and a second spring element also received around said slide member. The first spring element is effective for exerting a force F1 that would be typical of the force exerted during normal riding, while the second spring element is effective for exerting a force F2 that is greater than F1 that would be typical of the greater force exerted during jumping landing and take-off. In this regard, it is noted that in stadium jumping, participants compete in different jumping height divisions. For example, there is a 3xe2x80x26xe2x80x3 jump height division, a 4xe2x80x23xe2x80x3 jump height division, etc. Within each division, all of the jumps are relatively the same height. With the factors of rider weight and jumping height being substantially constant, the spring elements can be individually selected and customized according to a rider""s weight, height of jumps, and riding style. This is highly advantageous for marketing and sales purposes.
Turning back to the suspension, the lower end of the slide member is attached to the stirrup via a stirrup connector. During riding, the stirrup will move up and down relative to the housing with the slide member slidably moving within housing. A flange member at the top of the slide member compresses the first and second spring elements upon downward movement corresponding to the exertion of a downward force on the stirrup. During normal riding, the first spring is compressed to counter the downward forces exerted. The first spring will be compressed from a minimum load to a maximum load. However, when forces exerted during jumping exceed a percentage of the maximum force (load) on the first spring under compression, the second spring begins to compress to exert additional counter forces. The second spring will thereafter exert forces through its range of minimum compression to maximum compression.
In a first embodiment, the springs are concentrically configured around the slide member. The first, i.e. inner spring, has a longer length, and smaller diameter. The second spring has a shorter length and wider diameter and is received around the first spring. In operation, the flange first compresses the first spring through a range of motion. When the forces are great enough to compress the first spring through a predetermined range of compression, the flange then engages the second spring and begins compressing the second spring. In this regard, the first and second springs are simultaneously compressed and cooperate to exert a combined force against the flange.
In a second embodiment, the first and second springs are of the same length and diameter and are stacked one upon the other, the upper spring comprising the first spring and the lower spring comprising the second spring. In this regard, the first and second springs actively cooperate to exert forces against the flange and both are active at all times, in contrast with the first embodiment where the first spring is active to a certain point and then the second spring becomes active to cooperate with the first spring.
Accordingly, among the objects of the instant invention are: to provide a stirrup suspension for the rider of a horse to create additional suspension over and above what can be achieved physically through the flexion of the ankles; to provide a stirrup suspension that can be customized to individual needs based on body weight and height of jumping; to provide a multi-stage stirrup suspension to accommodate the different levels of downward force that occur during normal riding and jumping; to provide a stirrup suspension that is independent of the stirrup; to provide a stirrup suspension that improves the rider""s balance, performance and personal safety; to provide a stirrup suspension that reduces harmful contact with the horse""s back; to provide a stirrup suspension that reduces the structural breakdown of the stirrup strap; and to provide a stirrup suspension that reduces strain on the muscle, cartilage and ligaments of the rider""s knees, ankles and calves.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.